/*
 * File      : stack.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://openlab.rt-thread.com/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 */

#include <rtthread.h>

#include <i386.h>

/**
 * @addtogroup I386
 */
/*@{*/

/**
 * This function will initialize thread stack
 *
 * @param tentry the entry of thread
 * @param parameter the parameter of entry
 * @param stack_addr the beginning stack address
 * @param texit the function will be called when thread exit
 *
 * @return stack address
 */
rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
    rt_uint8_t *stack_addr, void *texit)
{
    unsigned long *stk;

    stk = (unsigned long *)stack_addr;
    *(--stk) = (unsigned long)parameter;
    *(--stk) = (unsigned long)texit;
    *(--stk) = 0x200;                       /*flags*/
    *(--stk) = 0x08;                        /*cs*/
    *(--stk) = (unsigned long)tentry;       /*eip*/
    *(--stk) = 0;                           /*irqno*/
    *(--stk) = 0x10;                        /*ds*/
    *(--stk) = 0x10;                        /*es*/
    *(--stk) = 0;                           /*eax*/
    *(--stk) = 0;                           /*ecx*/
    *(--stk) = 0;                           /*edx*/
    *(--stk) = 0;                           /*ebx*/
    *(--stk) = 0;                           /*esp*/
    *(--stk) = 0;                           /*ebp*/
    *(--stk) = 0;                           /*esi*/
    *(--stk) = 0;                           /*edi*/

    /* return task's current stack address */
    return (rt_uint8_t *)stk;
}
/*@}*/
